1. Field of the Invention
The present invention relates to a vehicle seat for automobiles and the like.
2. Description of the Related Art
Japanese Utility Model Application Laid-Open No. 62-111227 discloses one example of a conventional vehicle seat which is provided in automobiles and the like.
Referring to FIG. 5, a vehicle seat 70 has an upper arm 72 and a lower arm 74, each of which is formed from a press-formed iron product. An upper rail 76 of a seat track 80 is fixed to the underside of the lower arm 74 by means of unillustrated rivets or the like. A lower rail 78 of the seat track 80 is anchored to a vehicle floor (not shown) via brackets 81. A locking bracket 82 is secured by rivets 84 to a substantially central portion of the upper rail 76 in the longitudinal direction of the upper rail 76.
As illustrated in FIG. 6, an anchoring portion 86 of a seat belt is mounted to the lower arm 74 by portion of a weld bolt 73 and a nut 75, at which location a reinforcing member 88 is fixed by welding and the like for reinforcement. As shown in FIG. 5, the lower arm 74 is bolted to brackets 92 and 94 by means of bolts 96 at two points near both end portions of the lower arm 74 in the longitudinal direction of the lower arm 74. The brackets 92 and 94 are disposed near both end portions of a cushion frame 90 in the longitudinal direction of the cushion frame 90.
However, the vehicle seat 70 has a disadvantage in that the lower arm 74 is heavy because it is formed from a one-piece press-formed iron product. In order to overcome the disadvantage, a possible construction can be formed in which the lower arm 74 is integrally formed of any light metal such as aluminum, which is lighter than iron. Nevertheless, this structure still has an inconvenience in that the strength of the lower arm 74 is too low to sufficiently transmit a load from the lower arm 74 to the vehicle floor.